package com.clm.waimai.filter;

import com.alibaba.fastjson.JSON;
import com.clm.waimai.common.BaseContext;
import com.clm.waimai.common.R;
import jakarta.servlet.*;
import jakarta.servlet.annotation.WebFilter;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import java.io.IOException;

/**
 * 检查用户是否已经完成登录
 */
@WebFilter(filterName = "loginCheckFilter", urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {

    //路径匹配器，支持通配符
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        try{
            HttpServletRequest request = (HttpServletRequest) servletRequest;
            HttpServletResponse response = (HttpServletResponse) servletResponse;
            //1. 获取本次请求的url
            String requestURI = request.getRequestURI();
            log.info("拦截到请求：{}", requestURI);

            //定义不需要请求的路径
            String[] urls = new String[]{
                    "/employee/login",
                    "/employee/logout",
                    "/backend/**",
                    "/front/**",
                    "/common/**",
                    "/user/sendMsg",
                    "/user/login"
            };
            //2. 判断本次请求是否需要处理
            boolean check = check(urls, requestURI);

            //3. 如果不需要处理，则直接放行
            if(check) {
                log.info("本次请求{}不需要处理", requestURI);
                filterChain.doFilter(request, response);
                return;
            }

            //4-1 判断登录状态，如果已登录，则直接放行
            if(request.getSession().getAttribute("employee") != null){
                log.info("用户已登录，用户id为：{}", request.getSession().getAttribute("employee"));

                Long empId = (long) request.getSession().getAttribute("employee");
                BaseContext.setCurrentId(empId);

                //long id = Thread.currentThread().getId();
                //log.info("线程id为:{}", id);

                filterChain.doFilter(request, response);
                return;
            }

            //4-2 判断登录状态，如果已登录，则直接放行
            if(request.getSession().getAttribute("user") != null){
                log.info("用户已登录，用户id为：{}", request.getSession().getAttribute("user"));

                Long userId = (long) request.getSession().getAttribute("user");
                BaseContext.setCurrentId(userId);

                //long id = Thread.currentThread().getId();
                //log.info("线程id为:{}", id);

                filterChain.doFilter(request, response);
                return;
            }

            log.info("用户未登录");

            //5. 如果未登录则返回未登录结果，通过输出流方式向客户端页面响应数据
            response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
            return;
        }finally {
            BaseContext.removeCurrentId();
        }
    }

    /**
     * 路径匹配，检查本次请求是否需要放行
     * @param urls
     * @param requestURI
     * @return
     */
    public boolean check(String[] urls, String requestURI){
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if (match){
                return true;
            }
        }
        return false;
    }
}
